import java.lang.Math.*;
//class Stu {
//    private int a;
//    public int getA() {
//        return a;
//    }
//
//    public void setA(int a) {
//        this.a = a;
//    }
//}
class OutClass {
    static int a = 10;
    static int b=20;

    //静态内部类只能访问外部类static修饰的成员
    static class InClass {
        int a = 20;
        public void method() {
            a=30;
            b=2;
        }
    }
}
public class Test {
    public static void main(String[] args) {
        //局部变量使用时必须初始化
        //int a;
        //System.out.println(a);
        //成员变量不用，因为成员遍历JVM会自动赋值
        OutClass outClass = new OutClass();
//        OutClass.InClass inClass = new OutClass().new InClass();

        try {
            int[] arr={1,3,4};
            System.out.println(arr[5]);
        } catch (ArrayIndexOutOfBoundsException e) {
            System.out.println("s");
        } finally {
            System.out.println("ds");
        }
    }
}
